VMware vSphere ESXi 5.1
VMware vSphere ESXi 6.0
VMware vSphere ESXi 5.5
VMware ESX Server 3.5.x
VMware ESXi 3.5.x Installable
VMware ESX Server 2.5.x
VMware vSphere ESXi 5.0
VMware ESX 4.0.x
VMware ESX Server 3.0.x
VMware vSphere ESXi 6.7
VMware ESXi 4.0.x Embedded
VMware vSphere ESXi 6.5
VMware ESX 4.1.x
VMware vSphere ESXi 7.0.0
VMware ESXi 4.1.x Installable
VMware ESXi 3.5.x Embedded
VMware ESXi 4.1.x Embedded
VMware ESXi 4.0.x Installable
VMware vSphere ESXi 8.0

VMFS datastores cannot have their capacity reduced without destroying the original datastore.

To effectively reformat a VMFS datastore:

1. Backup or evacuate the content of the VMFS datastore. If hosts are running ESXi and storage vMotion is possible. Otherwise, a cold migration is necessary.
2. Perform a rescan of the storage from the datacenter level, make sure that all of the ESXi hosts were rescanned. See Performing a rescan of the storage on an ESX/ESXi host.
3. unmount the LUN and then un-present the LUN from all of the connected hosts. See How to detach a LUN device from ESXi hosts.
4. Present a new LUN of the desired size to the hosts requiring access to it and then rescan all hosts. See Performing a rescan of the storage on an ESX/ESXi host.
5. Create a new VMFS datastore with the desired size. See Create a VMFS Datastore.
6. Migrate/copy the data from the backup VMFS datastore to the newly created one.
7. If the new datastore is not visible on all hosts, perform a rescan. See Performing a rescan of the storage on an ESX/ESXi host.

Performing a rescan of the storage on an ESX/ESXi host
How to detach a LUN device from ESXi hosts
VMFS データストアのサイズを縮小する
减小 VMFS 数据存储的大小